qs full

1

1.0 Introduction

1.1 Introduction to the problem study

YTL Cement Sdn Bhd is one factory that produce concereteto their customers. This

company are located at Ampang , Selangor.In this study, we would like to identify the major

problem that related with the quality problems that occured in production department at YTL

Cement Sdn Bhd. First, we need to identify about the reject rate at the production department.

1.2 Objective of the study

To know what are the factor that influence the high rate of rejection of the product. To analyze the problems that they faced in production department To suggest the company how to reduce the reject rate.

2

2.0 Background of the Company

2.1 History

2.1.1 Corporate information

The YTL Corporation (YTL Corp) was founded by Tan Sri Dato' Seri (Dr.) Yeoh

Tiong Lay in 1955. His oldest son, Tan Sri Dato' Seri (Dr) Francis Yeoh Sock Ping, became

the Managing Director of YTL Corp in 1988. Under Tan Sri Dato' Seri (Dr) Francis Yeoh

Sock Ping's stewardship, the YTL Group grew from a single listed entity in 1985 to a force

comprising five listed companies. Today, YTL Corp is one of the Bursa Malaysia's largest

companies and together with its listed subsidiaries has a combined Market Capitalisation of

about RM37.2 billion (USD 12 billion). The company has also been listed on the Tokyo Stock

Exchange since 1996, being the first Asian non-Japanese company to be listed there.

YTL Group strategy of acquiring valuable assets at attractive or distressed price had

generated excellent returns for shareholders, successfully contributing to an annual average

compounded growth rate of 55% over the last 15 years. Over the last decade has seen the

group's portfolio of business had grown tremendously from a small construction firm into a

sprawling business empire involved in power, utilities, cement, construction, real estate,

information technology and leisure spanning across Asia-Pacific and Europe. These various

business units contributed at least RM1bil a year in dividends to YTL Corp and by 2015, the

dividend contribution is expected to double.

Amongst the group's key businesses are utilities, operating and maintenance (O&M)

activities, high speed rail, cement manufacturing, construction contracting, property

development, hotels & resorts, technology incubation, real estate investment trust (REIT), and

carbon consulting. YTL serves more than 12 million customers in over three continents.

In 2010 Malaysian Business Magazine Top 100 Companies survey of Malaysia’s

largest listed companies, YTL Corp has emerged as the largest non-government linked

company in Malaysia. YTL Corp has also been named as one of the Top 250 Global Energy

Companies in Asia under the Platts Top 250 Global Energy Company rankings and also

earned a ranking of 15 overall in the Fastest Growing Asian Companies.

3

2.1.2 YTL Cement

YTL Cement Bhd is one of the largest, most efficient and profitable manufacturers of

Cement and ready mixed concrete products in Malaysia with interest in Jurong Cement

Limited in Singapore and a 100% interest in Zhejiang Lin'an Jin Yuan Cement Co Ltd in

China.

4

2.2 Organizational Chart

ORGANIZATION CHART FOR AMPANG PLANT (B28)

DEPUTY G.MKC Lee

AREA MANAGERLow Kok Yong

PLANT MANAGERMohd. Nazri

QC ENGINEERRidhwan Aziz

PLANT MANAGERKantahn

ASST. SUPERVISORSanusi

BATCHERAita Bahadur

ASST. QC ENGINEERAmir

MAINTANENCE SUPERVISOR

A. Rajan

LOADER OPERATORM. Muniandy

GENERAL WORKERHari

Robert

SLUMPERMohd. Engkeng

PICKUP DRIVERMogan

MOBILE TECHNICIANFarid Adam

HafidiHasrul

MazhamSaiful

CONCRETE TECHNICIANAnil Kapoor

RajKhairulFaizalJamri

5

Figure 1 : Organizational Chart

Address: Messrs Aman Wangi Development, Lot 847, Lorong 2A Taman Seri Ukay, 68000 Ampang, Selangor Darul Ehsan

Contact Person : Muhd Ridhwan Aziz ( 019 – 6260736)

Total workers

Ampang Plant (B28) have 23 workers. All of them consist of 14 different areas which are lead by Deputy General Manager, Area Manager, QC Engineer, Plant Manager, Assistant Supervisor, Batcher, Assistant QC Supervisor, Maintenance Supervisor , Loader Operator, Slumper, General Worker, Pickup Driver, Mobile Technician, and Concrete Technician.

Marketing

The products are sending to nearer with Ampang’s area. The delivery of products are limited within 2 hours from the plant.

Type of products

YTL Ampang Plant is producing cement, sand, and concrete.

3.0 Total Quality Management (TQM)

3.1. Leadership

Leadership can be defined as the ability to positively influence people and systems to

have a meaningful impact and achieve results. In YTL Cement, in order to achieve the actual

quality standard, it is depends on attitude and action of the leader in the every department.

The company is stressful about the responsibility in order to monitor the growth of raw

materials such as sand, rock and cement. All test need to accomplish to every transmission of

these raw materials such as sieve analysis, silt content and etl. All the test will define the

quality of concrete. Once the test are undone, there will cause big defect to the product. Not

only that, it will causes the high quality problem. The leader needs to resolute and brave to

advice about the effect of quality.

6

3.2. Performance measurement

YTL Cement does the performance measurement by using collecting data, report,

analysis and others. For example, all data have been collected from the test (as mentioned

before) will be analyzed and will be recorded then it will be presenting in the meeting with the

board.

3.3. Customer satisfaction

Customers divide into to 2 types which is external customers and internal customers. External customers are those who receive the final products and normally at the organizational level. Internal Customers occur at the process and cross-departmental levels within the company. To identify customers there are some question need to answer as follows:-

What parts or products are produced?

Who uses our parts or products?

Who do we call, correspond/interact with?

Who supplied the inputs to the process?

For example, company must know about their customer feedback, discover customer need,

identify customer need and determine opportunities for improvement. At YTL Company,

there are two things that their customers want for their company which is delivery on time and

quality. Every customer wants their order at the time that they order. So, as supplier, they

always sent their concrete on the time. From now on company has many concrete orders from

their customers. One of way that they do to improve their productivity is adding concrete

truck and open new mix concrete plant nearer.

3.4. Employee Involvement

Employee involvement can measure by their education and training. The cost of education

and training for all personnel is enormous and the time to achieve it is lengthy. Educational

needs vary by function area, department and job. Quality Council may want to establish a

project team for the planning of the program. According to YTL Cement, there are two major

7

department in batching plants which are Quality Control (QC) and Operation. From time to

time, there will be a technician here that will give some briefing about the expansion of the

product (concrete). Meeting will be conducted everyday to discuss about all the problems

faced at the construction’s site. The discussion is about the method on how to solve the

problems related.

3.5. Continuos Process Improvement

In order to ensure the goal could be achieved, the company must do the continuous process

improvement. According to YTL Cement, this company always concerned their environment.

Their concrete also use recycle thing at their mixture. The mixture is replacing cement

utilization (OPC) too much. For produce cement, CO2 have been produce. One tan cement

can produces 1 tan CO2. They mix the recycle thing in the concrete to reduce cement

utilization.

4.0 Background of the Study

Manufacturing Process

Activities Flowchart

Figure 2 : Flowchart of Production

Receiving of material

Inspection Criteria Inspection Frequency

Quality Records Responsible Person

Monitoring of Aggregates Quality- sieve analysis Twice a

weekSeive Analysis Sheet Buildcon’s QC

Manager- silt content test Daily Silt Content Test

Form- color test Monthly Color Test Form- elongation test Monthly Ellongation Test

Form- flakiness index test Monthly Flakiness test result- moisture content Daily Moisture Content

Form

Computerised Production

Storage of Raw Material

Delivery of Concrete to Side

Receiving of Raw Material

8

Storage of Raw Material

Inspection Criteria Inspection Frequency

Quality Records Responsible Person

Monitoring of Sand Quality- sieve analysis Twice a

weekSeive Analysis Sheet Buildcon’s QC

Manager- silt content test Daily Silt Content Test

Form- color test Monthly Color Test Form- elongation test Monthly Ellongation Test

Form- flakiness index test Monthly Flakiness test result- moisture content Daily Moisture Content

FormMonitoring of Cement Quality- 8 cube samples for 1,3,7, and 28

Every 300 m3 Compression Work Sheet

Buildcon’s QC Manager

Monthly Statistical Analysis Report

Computerised Production

Inspection Criteria Inspection Frequency

Quality Records Responsible Person

Accuracy Check- Plant Cube Test Every load 3

MonthlyPlant Calibration Form

Buildcon’s Plant Manager

Calibration certificated

Finished Product Quality- Plant Cube Test Every 300 m3

of concreteMonthly Statiscal Buildcon’s QC

Manager- Slump Cube Test Every 300 m3

of concrete

Delivery of Concrete to Side

Inspection Criteria Inspection Frequency

Quality Records

Responsible Person

N/A N/A Buildcon’s Plant Manager

9

5.0 General Problems of Study

5.1 Slump Test For Cement

The slump cone is a right circular cone that is 12 inches high. The base of the cone is 8

inches in diameter and the top of the cone is 4 inches in diameter. The cone is filled with fresh

concrete in three layers of equal volume. Each layer is stroked 25 times with a rod that is ¾

inch in diameter. The end of the rod is bullet shaped. After the cone has been filled with

concrete and the concrete has been cut off level with the top of the cone, the cone is raised

vertically allowing the concrete to fall or slump. The distance that the concrete falls or slumps

from the original height is the slump of the concrete. Slump is measured in inches and is

reported to the nearest ¼ inch.

In the early days of concreting when concrete was composed of cement, aggregate and

water, the coarse aggregates determined the water content and the water determined the

slump. During this time a lower slump value meant a lower water content, which also meant a

higher quality of concrete.

Concrete is not only a blend of the three primary ingredients. There are typical

concrete may also contain admixtures, fibers and polymers. Therefore, the coarse aggregate

may not be the lone factor determining the water content of today's concrete. That means a

high or low slump may not be a clear indication of the quality of the concrete. In other words,

the slump cannot be used to directly determine the water content of a concrete mix.

Using modern technologies, a traditional concrete mix design with a natural 2-inch

slump may actually have a higher water content than that of a modern concrete mix design

with a 9-inch slump that contains a chemical superplasticizer. (A superplasticizer is a

chemical that is added to a concrete in order to increase the slump without adding

additional water.)

A mixture of stone, sand and water without cement will not flow like concrete, no

matter how much water you add. The reason for this is that it is the cement that gives concrete

its flowing properties. By chemically dispersing the cement grains a superplasticizer enables

cement to become a more effective lubricant, thereby increasing the slump without adding

additional water.

With the advent of chemical admixtures, slump can now be seen as either a water

slump or as a plasticized slump. If the slump is determined only by the water content, it is said

10

that the slump is a water slump. If the slump is determined by the water content and the

effects of a chemical admixture, it is said to be a plasticized slump.

Almost everything that the YTL CEMENT put into concrete can affect the slump. As

the air content of concrete is increased, the slump will also increase. Placing fibers into

concrete will decrease the slump. All factors have to be taken into account when designing a

concrete mix in order to produce concrete with a workable slump. The best slump from the

standpoint of workability and consolidation is 4 to 5 inches. Slump values in the 1 to 2-inch

range are not only hard to place, they are also hard to consolidate. On the other hand, slump

values above 6 inches may be prone to segregate and produce excessive bleed water.

Figure 3 : Method Slump Test

It should be pointed out that the slump test can only be used to determine the quality

of concrete from batch to batch within a given mix design. It cannot be used to determine the

quality of concrete from mix design to mix design. The slump does not determine the strength

of the concrete. That determination is made by the water-to-cement ratio.With the use of

modern admixtures in the mix designs of today, we can set the slump of the concrete at any

practical range we choose and still have good quality concrete.The purpose of a slump test is

to determine the consistency or texture of fresh concrete and to check its uniformity.

Uniformity or consistency of concrete is important to a successful concrete project.

The "slump" test is based on American Society for Testing and Materials C 143

"Standard Test Method for Slump of Portland Cement Concrete." If the slump test result is

outside of the slump range, correct before placing the concrete in the work. Make corrections

as follows:

11

Slump too low: Add water in measured amounts to bring the slump within the specified

range. Record the added water on the Certificate of Compliance.

Slump too high: Add additional cement by full bag to bring the slump within the specified

range. Provide cement from the same manufacturer as the original batch. Record the added

bags of cement on the Certificate of Compliance.

Based on figure

above, the slumped concrete takes various shapes, and according to the profile of slumped

concrete, the slump is termed as true slump, shear slump or collapse slump. If a shear or

collapse slump is achieved, a fresh sample should be taken and the test repeated. A collapse

slump is an indication of too wet a mix. Only a true slump is of any use in the test. A collapse

slump will generally mean that the mix is too wet or that it is a high workability mix, for

which slump test is not appropriate. Very dry mixes; having slump 0 – 25 mm are used in

road making, low workability mixes; having slump 165 – 235 mm3 are used for foundations

with light reinforcement, medium workability mixes; 50 - 90 for normal reinforced concrete

12

6.0 Data Collection and Result Analysis

6.1. Checksheet

Table 1 : Tally of Concrete nonconformities

Nonconformity Type Check TotalSlump Test III 3Exceed Time II 2Late Delivery I 1Breakdown I 1Others - 0

6.2. Pareto Diagram

Table 2 : Culmulative Frequency for nonconformities

Type Frequency % Frequency Culmulative Frequency

% Culmulative Frequency

Slump Test 3 42.9 3 42.9Exceed Time 2 28.5 5 71.4Late Delivery 1 14.3 6 85.7Breakdown 1 14.3 7 100Others 0 0 - -

slump fa

il

excee

d time

late d

elive

ry

breakd

ownothers

0

1

2

3

4

5

6

7

0

10

20

30

40

50

60

70

80

90

100

42.9

71.4

85.7

100

frequencypercentage cummulative

Figure 4 : Cumulative Line of Pareto diagram

13

6.3. Ishikawa Cause And Effect Diagram

Water Requirement Less surface area of Aggregate

Atittuide Quality of Materials Compaction

Temperature

Weather Mixing No proper measurement

Curing 

Figure 5 : Cause-and-Effect Diagram

Slump Fail

People Material Methods

Environment Equipment Measurement

14

6.3.1 People

Atittude

- People attituide in process to mixing the concreate can effect the slump test result. Better

supervision and attention can result better slump test.

6.3.2 Material

Water requirement

- When we use minimum water for lubrication of particle in aggregate, there is less shrinkage

which gives more strength by using same quantity of cement. Hence the strength depends on

water cement ratio.

Quality of material

- Quality of cement, sand and aggregate should be tested by various tests in the fields because

raw material of good quality gives maximum strength.

6.3.3 Method

Compaction

- Compaction of cement concrete mix using less water vibrated with vibrator. This

compaction will give same workability and more strength. Better compaction is achieved if

less water cement is used as the numbers of void will be less.

Less surface area of Aggregate

- Same cement can provide better coating to particle and it can enhance the strength. When

proper graded materials are used, lesser the voids in concrete, more the strength and tightness

in would be.  

6.4.4 Enviroment

15

Weather

- Weather in the time process of mixing concreat can effect the stickness and the

containing of water.

Temperature

- High temperature can effect less workability of concreat and low temperature can make

the concreate become to wet.

6.4.5 Equipment

Mixing

- Mixing should be done in mechanical mixer so that all constituents are thoroughly mixed

and become homogeneous without showing segregation.

Curving

- Cement needs water for its hydration. If water is inadequate, it will not hydrate completely

and therefore it will not be balanced properly causing inadequate strength. So all care should

be taken for proper curing of cement concrete. 

6.4.6 Measurement

No proper measurement

- When the water, cement and sand have mix in the silor, the quantity of water will diffrent

because the sand somtime already have the water.

16

6.4 Histogram for Slump Fail

Table 3: Number Nonconforming for Concrete

Number Nonconforming frequency

slump fail 3

exceed time 2

late delivery 1

Breakdown 1

Others 0

slump fail exceed time late delivery breakdown others0

0.5

1

1.5

2

2.5

3

3.5

Frequency Histogram

frequency

Number Nonconforming

Freq

uenc

y

Figure 6 : Frequency Histogram of Number Nonconforming for Concrete

Based on figure 4, we can identified that the highest number of nonconforming of the

reject rate is slump fail which is the frequency is 3 while the lowest number of nonconforming

is both of late delivery and breakdown. This data shows that the main problem that YTL

Cement Sdn. Bhd faced is about the slump fail. So, our group will determine how to reduce

that kind of number of nonconforming in order to help the company to increase their

productivity in producing its concrete.

17

6.5 Control Chart

Table 4 : Data of Standard Water of Concrete (m3)

subgroup date X1 X2 X3 ∑X X R1 172 212 195 579 193 402 189 195 170 554 184.67 253 230 189 180 599 199.67 414 180 202 189 571 190.33 225 250 212 230 692 230.67 386 190 190 200 580 193.33 107 172 196 210 578 192.67 388 200 201 250 651 217 509 205 196 210 611 203.67 14

10 180 189 255 624 208 7511 170 225 170 565 188.33 5512 475 335 420 1230 410 14013 210 206 245 661 220.33 3914 500 484 440 1424 474.7 6015 210 169 175 554 184.67 4116 169 198 203 570 190 3417 180 189 240 609 203 6018 179 202 210 591 197 3119 200 221 198 619 206.33 2320 210 229 175 614 204.67 5421 230 206 179 615 205 5122 172 179 185 536 178.67 1323 167 169 194 530 176.67 2724 180 180 220 580 193.33 4025 195 170 225 590 196.67 55

5442.3

8 1076

Based on table 6, we have take 25 subgroups of number of nonconforming, and 3

sample in order to identify the central limit, upper control limit and lower control limit for X-

bar chart and R chart.

18

19

Figure 7 : X - Chart for Slump Fail

Based on chart above, we can conclude that there are 2 point out of control for X-bar

Chart which is subgroup number 12 and 14. Both of this subgroup shows that there have

exceed the content of water in the concrete and its show the unusual pattern of the control

chart. So, our group need to do some revised control for the X- Bar Chart.

Figure 8 : X – Chart Revised for Slump Fail

Based on figure above, we have analyze the X – Chart Revised to determine if it stable

.Since the out of control of subgroup 12 and 14 on the X – Chart has an assignable cause, it

can be discarded from the data.

20

Figure 9 : R- Chart for Slump Fail

Based on chart above, we can conclude that there are 1 point out of control for R -

Chart which is subgroup number 12. This subgroup shows that there have exceed the content

of water in the concrete and its show the unusual pattern of the control chart. So, our group

need to do some revised control for the R- Chart.

Figure 10 : R-Chart Revised for Slump Fail

Based on figure 8, we have analyze the R– Chart Revised to determine if it

stable .Since the out of control of subgroup 12 on the R– Chart has an assignable cause, it can

be discarded from the data.

7.0 Discussion and Conclusion

Concrete is produced by mixing cement with fine aggregate (sand), coarse aggregate

(gravel or crushed stone), water, and—often—small amounts of various chemicals

called admixtures that control such properties as setting time and plasticity. The process of

hardening or setting is actually a chemical reaction called hydration. When water is added to

21

the cement, it forms a slurry or gel that coats the surfaces of the aggregate and fills the voids

to form the solid concrete. The properties of concrete are determined by the type of cement

used, the additives, and the overall proportions of cement, aggregate, and water.

To produce the good concrete, each aspect must be count properly starting from choosing the

material until the concrete send to the coutomer because each time take has effect to the

concrete mixing.

Sometime the labotary test should be done before comformation of the material of the

concrete choose because diffrent project of building required the diffrent concrete mixing.

The concrete can tell how long the building build can stand and still.

Event full automated machine still required the operator to start-it up, same to the production

of concrete, the workers also make a big role in the production line. Monitoring from the early

stage until the concrete send to the coustemer must be done properly to ensure the concrete

still in the best condition when the coustemer recive it.

In our opinion, the major problem in the plant is the time schedule from the coustomer

and their own self. Many concreate fail the slump test because their give the mix over water to

make the mixer running more smooft and it result the wet concreate. The coustomer also

frequently hold the order in the last minute make the concrete dry because it achieve the limit

time.

Another problem is the weather where is the company no have power to control it. The

temprecure over the plant also give the effect to the concreate. In the rainning season, the

plant have to beware with the quantity of water because the sand already conitaining the water

and the spring season, the hot temperature will make the concrete dry fast then usualy.

22

References

http://www.ytlcement.com

http://my.wowcity.com/ampang/locbus2/5074331509062771121/ytl-corporation-bhd.htm

http://en.wikipedia.org/wiki/Concrete_slump_test

23

24

Appendices